Take a close look at how a typical house is built and you’re likely to discover that instead of having one foundation, it has several. Sometimes multiple foundations can increase the likelihood of foundation problems. Basements, Slabs, Crawl Spaces,…
Here in the Northeast, a typical house will have a basement foundation under the main living area and a slab foundation under the garage. But the house might also have a poured-concrete patio, which also qualifies as a slab foundation. It could also have a deck, built on a pier-and-post foundation.
When a growing family decides that they need some extra space, the addition they build will probably have a crawl space foundation rather than a full basement. Compared to building a basement foundation, a crawl space foundation can be built more quickly, more affordably and with less damage and disruption to the property. This explains why many older homes that have been expanded and/or remodeled have basement as well as crawl space and slab foundations.
More Foundations Can Mean A Greater Chance of Foundation Problems. An older house that has been remodeled or added onto probably has foundations that were built by numerous contractors. Homeowners may have even decided to do some of the work themselves, completing a poured-concrete slab for a patio without a builder’s help, for example. With multiple builders adding foundations at different times, there’s a greater chance that problems may develop -slabs that crack because of inadequate reinforcement or missing control joints, crawl space walls that settle because of soft soils with poor load-bearing qualities, and so on.
Even with sound foundation construction practices are followed, there can be problems that develop over time. For example, consider the situation that occurs when a dirt-floored crawl space foundation is added onto an existing basement foundation. The basement may have been clean and dry before the addition, but that status will change as moisture from the new crawl space migrates into the basement area. Completing the crawl space without sealing out the moisture will introduce high humidity into both foundations, along with the strong likelihood that mold and insect damage will follow.
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